Plants, such as a power generation plant, a steel plant, and a chemical plant, are controlled by a plant monitoring-controlling system that controls various facilities in each plant. Such a plant monitoring-controlling system includes a plant control device and an operating-monitoring device, etc.
The plant control device controls control targets. The operating-monitoring device operates and monitors the control target through the plant control device. The plant control device and the operating-monitoring device respectively run software for control as well as software for operation and monitoring on an operating system.
The plant control device and the operation-monitoring device are connected to a network in order to transmit/receive control and operating-monitoring signals.
In such plant monitoring-controlling system, conventionally, an operating system, software for control, and software for operation and monitoring which are developed by individual manufacturer are used. Moreover, an exclusive network for signal transmission/reception is used. Hence, a risk like a virus attack from the exterior is little.
Nowadays, there is a tendency that a large number of systems use general-purpose hardware, software and network from the standpoint of the cost reduction and the easiness of installation and maintenance.
Because of the same reason, in a plant monitoring-controlling system, there is also a tendency that a personal computer in which a general-purpose operating system has been installed is used as the plant control device and the operating-monitoring device. Moreover, a public line network is utilized as the network in some cases.
In this case, however, the possibility that devious programs such as computer virus enter through the network or the USB port, etc., of the personal computer increases.
In order to address such a disadvantage, it is possible to run a general-purpose antivirus software to periodically check the presence/absence of a virus infection. When, however, such antivirus software is being run, the load factor of a CPU increases. Hence, the operation of the operating system, software for the control, and software for operation and monitoring may become slow.
In particular, a plant subjected to a control highly needs to keep operating for long years. Accordingly, a delay or a termination of an operation due to an external cause must be avoided as much as possible.
Embodiments of the present invention have been proposed in order to address the above-explained disadvantages, and it is an object to provide a technology that can ensure a high security without affecting a plant operation.
In order to accomplish the above object, a plant security managing device according to the embodiments of the present invention has following technical features:
(1) a determining unit that determines which one of elements multiplexed as a service system and a standby system associated with monitoring and controlling of a plant is the standby system;
(2) a security processing unit that performs a security process only on the element that is the standby system; and
(3) a change instructing unit that outputs an instruction for changing the standby-system element and the service-system element with each other.
The embodiments of the present invention can be deemed as a method for realizing respective functions of the above-explained units by a computer or an electronic circuit, and a program run by a computer.